ArticleLancet regional health. Americas2022
Influence of age on the effectiveness and duration of protection of Vaxzevria and CoronaVac vaccines: A population-based study.
Article in Lancet regional health. Americas, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 57 papers, 1 of them a synthesis that pooled it.
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
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Who cites it
57 citing papers in PubMed, 1 synthesis or guideline pooled it, 100 citations in OpenAlex.
- Effectiveness of heterologous and homologous covid-19 vaccine regimens: living systematic review with network meta-analysis.BMJ (Clinical research ed.) · 2022Pooled it
- Trial
- Interaction of TNFi and conventional synthetic DMARD in SARS-CoV-2 vaccine response in axial spondyloarthritis and psoriatic arthritis.Joint bone spine · 2023Trial
- Immunogenicity, Effectiveness, and Safety of Inactivated Virus (CoronaVac) Vaccine in a Two-Dose Primary Protocol and BNT162b2 Heterologous Booster in Brazil (Immunita-001): A One Year Period Follow Up Phase 4 Study.Frontiers in immunology · 2022Trial
- Effectiveness, Safety, and Immunogenicity of a Second COVID-19 Vaccine Booster in the Elderly: A Systematic Review and Meta-Analysis Protocol.Health science reports · 2026Article
- Seroprevalence, immune response dynamics, and incidence of COVID-19 after CoronaVac vaccination in a fully vaccinated small municipality in Northeast Brazil: a population-based surveillance study.BMC infectious diseases · 2026Observational
- Health policies in Brazil (2016-2022): neoliberalism, pandemic, and threats to the Brazilian Unified National Health System.Cadernos de saude publica · 2026Article
- COVID-19 vaccination remains essential for healthcare professionals: clinical evidence from a Polish cross-sectional study.Frontiers in public health · 2026Article
- Sociodemographic and Occupational Factors Associated With COVID-19 Vaccine and Influenza Vaccine Uptake Among Healthcare Workers, in Albania, 2022-2023: A Multicenter Study.Clinical infectious diseases : an official publication of the Infectious Diseases Society of America · 2025Article
- Skewed pulmonary innate immune cell composition underlies the delayed influenza clearance in aged mice.Frontiers in microbiology · 2025Article
- Induction of Fc-dependent functional antibodies against different variants of SARS-CoV-2 varies by vaccine type and prior infection.Communications medicine · 2024Article
- Comparison of different T cell assays for the retrospective determination of SARS-CoV-2 infection.The Journal of general virology · 2024Article
- Development of T follicular helper cell-independent nanoparticle vaccines for SARS-CoV-2 or HIV-1 by targeting ICOSL.NPJ vaccines · 2024Article
- Estimating All-Cause Deaths Averted in the First Two Years of the COVID-19 Vaccination Campaign in Italy.Vaccines · 2024Article
- The role of vaccines in the COVID-19 pandemic: what have we learned?Seminars in immunopathology · 2024Review
- Second booster dose improves antibody neutralization against BA.1, BA.5 and BQ.1.1 in individuals previously immunized with CoronaVac plus BNT162B2 booster protocol.Frontiers in cellular and infection microbiology · 2024Article
- Relative vaccine effectiveness of mRNA COVID-19 boosters in people aged at least 75 years during the spring-summer (monovalent vaccine) and autumn-winter (bivalent vaccine) booster campaigns: a prospective test negative case-control study, United Kingdom, 2022.Euro surveillance : bulletin Europeen sur les maladies transmissibles = European communicable disease bulletin · 2023Article
- Effectiveness of COVID-19 vaccines against hospitalisation in Latin America during three pandemic waves, 2021-2022: a test-negative case-control design.Lancet regional health. Americas · 2023Article
- Memory B cell development elicited by mRNA booster vaccinations in the elderly.The Journal of experimental medicine · 2023Article
- Evidence of leaky protection following COVID-19 vaccination and SARS-CoV-2 infection in an incarcerated population.Nature communications · 2023Article
Corrections and comments
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Authors and funding
13 authors at 6 institutions in 2 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundAging influences COVID-19 severity and response to vaccination, but previous vaccine effectiveness (VE) analyzes lack the power to evaluate its role in subgroups within the elderly age group. Here we analyzed the impact of age on viral vector and inactivated virus vaccines' effectiveness, the main platforms used in low- and middle-income countries.
methodsWe report a retrospective longitudinal study of 75,919,840 Brazilian vaccinees from January 18 to July 24, 2021, evaluating documented infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), COVID-19-related hospitalisation, ICU admission, and death. Negative binomial regression models adjusted for sociodemographic characteristics were used for VE estimation.
findingsThe overall analyzes of full vaccination showed VE against hospitalisation, ICU admission, and death of 91·4% (95%CI:90·1-92·5), 91·1% (95%CI:88·9-92·9) and 92·3% (95%CI:90·5-93·7) for Vaxzevria and 71·2% (95%CI:70·0-72·4), 72·2% (95%CI:70·2-74·0) and 73·7% (95%CI:72·1-75·2) for CoronaVac, respectively. VE for all outcomes is progressively lower with age. In fully-Vaxzevria-vaccinated individuals aged <60 years, VE against death was 96.5% (95%CI:82.1-99.3) versus 68·5% (95%CI:40·0-83·4) in those ≥90 years. Among fully-CoronaVac-vaccinated individuals, VE against death was 84.8% (95%CI:77.1-89.9) in those <60 years compared to 63.5 (95%CI 58.7-67.7) for vaccinees aged 80-89 years and 48·6%; (95%CI:35·0-59·3) for individuals aged ≥90 years. Post-vaccination daily cumulative incidence curves for all outcomes showed increased risk from younger to elder decades of life. There was no increase in the incidence of hospitalisation for individuals <60 years vaccinated during the same period as those aged ≥90 years.
interpretationAlthough both vaccines have been effective in protecting against infection, hospitalization and death; Vaxzevria and CoronaVac demonstrated high effectiveness against severe outcomes for individuals up to 79 years of age. Our results reinforce the idea that booster doses should be carefully considered in elders.
fundingThis study was partially supported by a donation from the "Fazer o bem faz bem" program.
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